The present invention relates to electronic timepieces and more particularly to a control device for setting a timepiece having a digital display.
In order to set an electronic timepiece it is necessary, in principle, to correct each counter, i.e. minute, hour and day counters, because it is difficult to accurately set the timepiece with a variable speed clock pulse generator (quick for rough adjustment, then progressively slower as the correct time is approached) and because the electronic circuits are not necessarily adapted to an excessively high input frequency. If, for instance, the hours display is to be set at the rate of two units/second, it will be necessary to supply the seconds counter with pulses having a frequency over 7000 Hz. In addition, the adjustment of time between various time-zones and date (at the end of a 30-day month) should be done without disturbing the normal working of the watch.
A simple well-known solution is to provide the watch with buttons each corresponding to a specific function, for instance:
A BUTTON FOR ENABLING THE ADJUSTMENT OF THE DATE DISPLAY AT A RATE OF ONE UNIT/SECOND, WHILE THE REMAINING PARTS OF THE WATCH CONTINUE TO WORK NORMALLY;
ANOTHER BUTTON TO CORRECT THE HOURS DISPLAY AT A RATE OF ONE UNIT/SECOND, WITH THE PASSING OF THE 24 HOURS POINT HAVING PREFERABLY NO INFLUENCE ON THE ADVANCE OF THE DATE, MINUTES AND SECONDS DISPLAYS WHICH RUN NORMALLY;
A THIRD BUTTON FOR CORRECTION OF THE MINUTES DISPLAY WITH PREFERABLY NO ADVANCE OF THE HOURS DISPLAY AT THE 60 MINUTES POINT, THE SECONDS AND HOURS DISPLAYS RUNNING NORMALLY;
FINALLY A FOURTH BUTTON TO STOP THE SECONDS COUNTER AND RESET THE SAME TO ZERO. This method enables setting of the timepiece in any way and it is easy to identify the function to be performed, either by marking the buttons or by their positions geometrically associated with respect to the display.
The present invention tends to solve the problem of setting a watch the display of which normally shows only hours and minutes, but which can also show date and second on the same display, if wanted. This problem could be controlled with the four buttons mentioned above and an additional one for date and seconds. This solution, however, has a disadvantage: handling of two buttons is necessary to fix the date, which handling is not very convenient.
In another prior art arrangement the number of buttons is reduced to two, i.e. a rotating switch whose different positions correspond to well-defined functions and a push button to perform the selected function.